Llrsb : Privacy-Preserving Epidemic Infection Control Scheme Through Lattice-Based Linkable Ring Signature in Blockchain

Epidemics, such as COVID-19, have serious consequences globally, of which the most effective way to control the infection is contact tracing. Nowadays, research releated to privacy-preserving epidemic infection control for has been conducted, nevertheless, current researches do not regard the authenticity of records and infection facts as well as poor traceability. Moreover, with the emergence of quantum computing, there is a bottleneck in upholding privacy, security and efficiency. Our paper proposes a privacy-preserving epidemic infection control scheme through lattice-based linkable ring signature in blockchain, called LLRSB. Firstly, our scheme adopts a blockchain with three ledgers to store information in a distributed manner, which offers transparency and immunity from the Single Point of Failure(SPoF) and Denial of Service (DoS) attacks. Moreover, we design a lattice-based linkable ring signature scheme to secure privacy-preserving of epidemic infection control. Significantly, we are the first to propose a privacy-preserving epidemic infection control scheme that can resist quantum computation attacks and achieve traceability. Security analysis indicates that our privacy-protected infection control scheme ensures unconditional user anonymity, record unforgeability, signature linkability, link nonslanderability and contact traceability. Finally, the comprehensive performance evaluation demonstrates that our scheme has an efficient time-consuming, storage consumption and system communication overhead and is practical for epidemic and future pandemic privacy-preserving